Conventionally, soil compaction techniques are often utilized to create surfaces to support building foundations, roadways, and retaining structures. It is desirable to have consistent and level compacted soil. Many methods are available for soil compaction, such as static compaction, dynamic compaction, and vibrating compaction. Static compaction may include placing a compaction weight on the area requiring compaction, and leaving the compaction weight in place for a certain period of time. Dynamic compaction involves lifting a compaction weight into position, and repeatedly dropping the compaction weight onto the desired location. Vibrating compaction involves stressing a location to be compacted through vibratory movement of a hammer or plate.
Typical operation of a conventional dynamic compaction deployment begins with the manual layout of an operational grid over the construction site. The operational grid may include a plurality of drop locations over which the compaction weight is to be dropped. Standard techniques for marking the drop locations may include the positioning of sandbags over the drop locations as measured and positioned by hand or by using handheld satellite navigation receivers. Once the drop locations have been marked by the placement of sandbags, the compaction machines are navigated manually by an operator to the marked drop location, and the compaction weight placed on the ground at the drop location. Compaction machines typically include mobile cranes with a telescoping boom, which is used to hoist, move, and drop the compaction weight.
The initial elevation of the drop location, or alternatively the initial elevation of the compaction weight, is then determined through manual measurement by using an optical level and staff. The weight is then reattached to a winch cable of the compaction machine and lifted to a predetermined drop height. Once in position, the operator releases the compaction weight, dropping the compaction weight repeatedly for at least a minimum number of drops. Drop-to-drop displacement, total ground displacement, and target displacements are similarly measured and recorded manually. Using this conventional methodology, absolute elevations are not utilized and all data is captured relative to the initial elevation of the drop location or alternatively the initial elevation of the compaction weight.
Due to user error and inconsistencies introduced by the process of manually positioning the compaction weight, and measuring ground displacement, conventional dynamic compaction processes result in errors and non-uniform compaction results between drop locations of the operational grid. Moreover, conventional operating procedures for dynamic compaction pose risks to operators and contractors on the ground during initial positioning of the compaction weight. For example, because compaction weights themselves often have a radius in excess of 1 m, and are carried between points close to the ground, the sand bag marking a drop location may be obscured to the operator by the compaction weight, resulting in errors in the positioning of the compaction weight. In some cases, a contractor on the ground may act as a spotter to assist the operator in navigating and aligning the compaction weight over the sand bag. However, this may expose the spotter to risk of injury, and does not necessarily eliminate alignment error. Additional error and safety risks are introduced in the manual measurement of drop-to-drop ground displacement, and total ground displacement. Furthermore, efficiency and productivity are limited by the time it takes to manually layout and mark the drop locations of an operational grid, navigate to a drop location, align the compaction weight over the drop location marker, and measure ground displacement for each drop.
Thus, an improved system for dynamic compaction is presented by the embodiments below.